It's perfectly possible to install 10.4 on a G4. Just make sure you've got (i) a DVD drive for installing OS X, and (ii) the original retail OS X Tiger installation DVD. You can't take the installation disk from an iMac, for example, it must be the "normal" retail DVD, because all the other installation disks are made for a specific Mac model.

It's perfectly possible to install 10.4 on a G4. Just make sure you've got (i) a DVD drive for installing OS X, and (ii) the original retail OS X Tiger installation DVD. You can't take the installation disk from an iMac, for example, it must be the "normal" retail DVD, because all the other installation disks are made for a specific Mac model.

Also you naturally can't install version that is intended for Intel either.